There is a misconception that all verbs in a paragraph should be in the same tense. The choice of the appropriate verb tense depends on context and meaning.

The duo explain the difference between the present tense and past tense in a way that ... and encourage learning through curriculum-linked topics. KS1 English: Grammar Rules with Braydon Bent ...

Use the past tense to report what happened in the past ... increases linearly over time in such circumstances. In English, verbs can express an action in one of two voices. The active voice ...

One’s tense will vary depending on what one is trying to convey within their paper or section of their paper. For example, the tense may change between the methods section and the discussion section.